The present invention relates to continuous form electrophotographic printers, and more specifically to a structure and control method for a fixing unit for fixing toner images to continuous form paper.
Conventionally, continuous form electrophotographic printers have some method of separating a fixing heat roller from the continuous form paper when a fixing operation is idle, so that the paper will not become deformed or scorched. It is known to lower a pressure roller away from a heat roller where the heat roller is positioned above the paper path, so that the paper will follow the pressure roller down and away from the heat roller.
However, if the apparatus for separating the pressure roller is arranged so that the paper path bends at the contact point between the pressure and heat rollers, inconsistent fixing and poor speed control can result. Furthermore, if the paper is not driven during the separation phase, the paper tends to stick to the heat roller by the adhesive properties of melted toner.
For these reasons there exists a need for an electrophotographic printer able to separate a toner-bearing page from a heat roller reliably and effectively, and without bending the paper path at the fixing interface.